According to a report performed by IDC Research:
organizations perceived open source technology as providing better security compared to proprietary products...
In reality, it seems that the advantages of open source security are taking hold, so much in fact, that they are the primary reason for adoption in Asia and the region. So maybe, when Microsoft and other firms can't artificially meddle with the system, look what happens - the people speak and the choice is clear.
Is the reason because proprietary versions are so insecure, that Linux is secure by comparison? Or is it that Linux, by nature, gets more attention from a driven community to create platforms that are inherently better engineered, for more security through development?